1. Field of the Invention
This invention relates to a positioning operation for attaching a screen plate including a frame and a screen to a screen printer. The screen plate might be also called as a stencil plate, stencil sheet, screen-mesh, etc.
2. Description of the Related Art
FIG. 5 explains an operation of attaching a screen plate according to the related art.
In FIG. 5, a work 53 is placed on a table 51. Work positioning marks 54 and 55 are written on the work 53. A screen plate 60 includes a frame 61 and a screen 63. The screen plate 60 is attached to frame fixing units 66 and 67 so that plate positioning marks 64 and 65 written on the screen 63 respectively correspond to the work positioning marks 54 and 55. In the related art, the plate positioning mark 64 and the work positioning mark 54 were matched and the plate positioning mark 65 and the work positioning mark 55 were matched just by looking with eyes. After the screen plate 60 was attached, printing for trial was repeated a few times to make a minor adjustment in an attaching position of the screen plate 60. In this way, the attaching position of the screen plate 60 was determined.
The screen 63 is a screen-mesh, or the screen 63 is made of a metal. Therefore, even if positioning is tried from a position above the screen 63, it is impossible to look at the work positioning marks 54 and 55 which are under the screen 63. Therefore, positioning was performed only by guessing, and it was necessary to print for trial a few times after positioning. The positioning was performed by trial and error.
It is one of objects of this invention to provide a screen printer and a method for setting the screen plate in which the screen plate is able to be attached at a right position in a stage of initializing the screen printer, i.e., so-called alignment stage.
According to an aspect of this invention, a screen printer for performing screen printing by matching positions of a work and a screen plate includes a pointing unit for pointing at a work positioning mark on a work by a pointer. A plate positioning mark on the screen plate is positioned to be matched with the pointer of the pointing unit once the work positioning mark has been pointed by the pointer of the pointing unit.
According to another aspect of this invention, a method for setting a screen plate includes setting a work at a printing position, pointing a light beam at a work positioning mark on the work, and setting a position of the screen plate to match a plate positioning mark on the screen plate with the light beam.
According to another aspect of this invention, the screen printer includes a table for placing a work including a work positioning mark, a pointing unit for pointing by a pointer at the work positioning mark on the work placed on the table, and a fixing unit for fixing a screen plate including a plate positioning mark to be positioned for being matched with the pointer of the pointing unit pointing at the work positioning mark.
Further features and applications of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
Other objects features, and advantages of the invention will be apparent from the following description when taken in conjunction with the accompany drawings.